Map used to define Nebraska Sandhills doesn't include nearby areas also vulnerable to contamination, InsideClimate News has learned.

"A relatively modest jog around the Sandhills"—that's how one TransCanada executive describes the Keystone XL oil pipeline's new route through Nebraska, which is expected to be released in the next few weeks.

But while the path will avoid the Nebraska Sandhills—a region of grass-covered sand dunes that overlies the critically important Ogallala aquifer—it could still pass through areas above the Ogallala, where the water supply is vulnerable to the impacts of an oil spill.

The original Keystone XL would have crossed through 100 miles of the Sandhills on its way from the tar sands mines of Alberta, Canada to refineries on the U.S. Gulf Coast. But TransCanada agreed to reroute it in November, after thousands of Nebraskans joined environmentalists to protest the pipeline's path over the aquifer.

The aquifer spans eight states and supplies 83 percent of Nebraska's irrigation water. It's also connected to the High Plains aquifer, which in many places lies above the Ogallala aquifer. Although residents of the Sandhills technically rely on the High Plains aquifer for drinking and irrigation, most refer to the Ogallala aquifer when talking about their water supply.

"It was always about the water," said Amy Schaffer, a fifth-generation Nebraskan whose father runs a Sandhills ranch. "This isn't over until they get [the pipeline] out of the Ogallala aquifer."

The map delineates the borders of the Sandhills, but scientists say it's a general-use map designed for ecosystem management. When it comes to groundwater and an area's vulnerability to an oil spill, the map doesn't encompass all the sensitive regions.

"I think if you're protecting the ecological aspects of the Sandhills, the boundary we have is probably better than any of the other [available maps]," said James Omernik, a retired EPA scientist who was one of the map's principal authors. "If you are more concerned about the water table or sandy [soil] or any other characteristic, then you might want to build a buffer around the Sandhills that would include the characteristic you're trying to protect."

TransCanada did not return calls for this article. But last week, Alex Pourbaix, president of TransCanada's energy and oil pipeline division, told reporters that the new route will add about 20 miles to the overall pipeline. That means the pipeline would run close to the edge of the Sandhills, through areas where scientists say the water table is high and the soil is sandy, just as it is in the Sandhills itself.

Schaffer says TransCanada's short detour isn't enough.

"If they're not going to be generous about the Sandhills boundary," we're going to continue to protest, she said. "TransCanada is putting in as little effort as they can. They're not taking our water and land seriously."

John Bender, a water quality standards coordinator at the Nebraska DEQ, said the ecoregions map is just the first step of the rerouting process. Now that the agency has identified the Sandhills, he said it's up to TransCanada to "come up with something that's as far away from [the Sandhills] as possible while still meeting their needs."

Landowners, DEQ Disagree on Sandhills Map

Although TransCanada has been tight-lipped about the new route, company spokesman Shawn Howard has said in previous interviews with InsideClimate News that the reroute will affect only Nebraska. That means the pipeline would still cross the South Dakota/Nebraska boundary at the original entry point in eastern Keya Paha County. From there, it would have to go east, because moving it west would take it further into the Sandhills.

If only 20 miles are being added to the route, the pipeline will likely run southeast through northern Holt County. That area is part of the northwestern glaciated plains, an ecoregion east of the Sandhills. The water table there is so high that in the spring, the groundwater often rises enough to flood some fields with standing water.

The soils are a hybrid between the permeable soil found in the Sandhills and the fine, clay-based soil further east, said Dave Wedin, a grasslands expert at the University of Nebraska-Lincoln. "I can't give you percentages. It becomes case by case as you go through there."

Many landowners want the Keystone XL rerouted 100 miles east, parallel to an existing TransCanada oil pipeline that is buried in clay-based soil. That soil would act as a barrier between an oil spill and the underlying aquifer, said Sandhills rancher Terry Frisch.

"We've been called environmental radicals ... [but] we're just looking out for our livelihood," Frisch said. He pointed out that regulators are still struggling to clean up a 2010 tar sands oil spill on the Kalamazoo River, and that a spill in an underground aquifer like the Ogallala would be even harder to contain.

A group of landowners, including Schaffer and Frisch, tried to convince the DEQ that the ecoregions map shouldn't be used to plan the pipeline reroute. Last month, they shared their concerns with Nebraska Gov. Dave Heineman. The governor listened politely, Schaffer said, but made no promises.

Schaffer is also disappointed with the DEQ. The reroute was supposed to be a "public and transparent process," she said. But although the landowners requested a meeting with the DEQ in December, the agency didn't meet with them until January, after the ecoregions map had been chosen.

At that meeting, the landowners discovered that DEQ hadn't conducted any fieldwork to determine the edges of the Sandhills.

Bender, the DEQ water expert, told InsideClimate News that the agency "looked at all the information we could round up on what might constitute a definition of the Sandhills ... and all the evidence seemed to point to the ecoregions map as a fairly encompassing [representation] of what we could use."

Omernik, the map's co-author, said the ecoregions map was designed for general ecosystem management. Ecoregions are areas that share similar ecosystem characteristics, he said, with each ecoregion defined by a wide range of factors including climate, vegetation, topography, hydrology and human impacts such as land use.

"If you're only looking at the hydrologic characteristics, that wouldn't be the same as the Sandhills boundary," Omernik said. The ecoregions map was designed for general use, and "if people are interested in a specific [factor], then they need to look at that specifically."

Bender said the DEQ would consider all environmental factors once TransCanada reveals the proposed route. But he pointed out that it hasn't yet been determined whether the agency will take part in the environmental review.

State Sen. Jim Smith recently introduced a bill that would allow the DEQ to continue its review in the absence of an active pipeline application. That bill was voted out of committee yesterday and will be brought before the full legislature. But if it doesn't pass, the pipeline's environmental review would likely pass to Nebraska's Public Service Commission, which was given regulatory control over oil pipelines under a state law passed in November.